Optimize AArch64 handling of 32-bit personality
By putting aarch64_regs and arm_regs into a union,
register copying is eliminated.
No need to check and change personality on syscall exit.
* defs.h: Remove unused NUM_ARM_REGS define. Fix indentation.
* syscall.c: Put aarch64_regs and arm_regs into a union.
(update_personality): Shorten bitness message.
(printcall): Add commented-out PC printing.
(get_regs): Remove now-unnecessary 64-to-32 bits register copying.
(get_syscall_result): Drop personality changing code.
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
diff --git a/syscall.c b/syscall.c
index 3385c24..fcd4850 100644
--- a/syscall.c
+++ b/syscall.c
@@ -295,7 +295,7 @@
}
# elif defined(AARCH64)
if (!qflag) {
- static const char *const names[] = {"32-bit ARM", "AArch64"};
+ static const char *const names[] = {"32-bit", "AArch64"};
fprintf(stderr, "[ Process PID=%d runs in %s mode. ]\n",
tcp->pid, names[personality]);
}
@@ -681,8 +681,12 @@
#elif defined(ARM)
struct pt_regs arm_regs; /* not static */
#elif defined(AARCH64)
-static struct user_pt_regs aarch64_regs;
-static struct arm_pt_regs arm_regs;
+static union {
+ struct user_pt_regs aarch64;
+ struct arm_pt_regs arm;
+} arm_regs_union;
+# define aarch64_regs arm_regs_union.aarch64
+# define arm_regs arm_regs_union.arm
static struct iovec aarch64_io = {
.iov_base = &aarch64_regs
};
@@ -816,7 +820,8 @@
tprintf("[%08lx] ", pc);
#elif defined(ARM)
tprintf("[%08lx] ", arm_regs.ARM_pc);
-/*#elif defined(AARCH64) ??? */
+#elif defined(AARCH64)
+ /* tprintf("[%016lx] ", aarch64_regs.regs[???]); */
#elif defined(AVR32)
tprintf("[%08lx] ", regs.pc);
#elif defined(BFIN)
@@ -868,21 +873,22 @@
/*aarch64_io.iov_base = &aarch64_regs; - already is */
aarch64_io.iov_len = sizeof(aarch64_regs);
get_regs_error = ptrace(PTRACE_GETREGSET, pid, NT_PRSTATUS, (void *)&aarch64_io);
+# if 0
+ /* Paranoia checks */
if (get_regs_error)
return;
switch (aarch64_io.iov_len) {
- case sizeof(regs):
- /* We are in 32-bit mode */
- memcpy(&arm_regs, &aarch64_regs, sizeof(arm_regs));
- break;
case sizeof(aarch64_regs):
/* We are in 64-bit mode */
- /* Data is already in aarch64_regs */
+ break;
+ case sizeof(arm_regs):
+ /* We are in 32-bit mode */
break;
default:
get_regs_error = -1;
break;
}
+# endif
# elif defined(SPARC) || defined(SPARC64)
get_regs_error = ptrace(PTRACE_GETREGS, pid, (char *)®s, 0);
# elif defined(TILE)
@@ -1113,9 +1119,9 @@
scno = aarch64_regs.regs[8];
update_personality(tcp, 1);
break;
- case sizeof(regs):
+ case sizeof(arm_regs):
/* We are in 32-bit mode */
- scno = arm_regs.uregs[7];
+ scno = arm_regs.ARM_r7;
update_personality(tcp, 0);
break;
}
@@ -1627,7 +1633,7 @@
for (i = 0; i < nargs; ++i)
tcp->u_arg[i] = aarch64_regs.regs[i];
else
-# endif /* AARCH64 */
+# endif
for (i = 0; i < nargs; ++i)
tcp->u_arg[i] = arm_regs.uregs[i];
#elif defined(AVR32)
@@ -1861,14 +1867,16 @@
return -1;
if (upeek(tcp, PT_R10, &ia64_r10) < 0)
return -1;
+#elif defined(ARM)
+ /* already done by get_regs */
#elif defined(AARCH64)
-/* FIXME: uh, why do we do it on syscall *exit*? We did it on entry already... */
+ /* register reading already done by get_regs */
+
+ /* Used to do this, but we did it on syscall entry already: */
/* We are in 64-bit mode (personality 1) if register struct is aarch64_regs,
* else it's personality 0.
*/
- update_personality(tcp, aarch64_io.iov_len == sizeof(aarch64_regs));
-#elif defined(ARM)
- /* already done by get_regs */
+ /*update_personality(tcp, aarch64_io.iov_len == sizeof(aarch64_regs));*/
#elif defined(M68K)
if (upeek(tcp, 4*PT_D0, &m68k_d0) < 0)
return -1;
@@ -2049,7 +2057,7 @@
}
}
else
-# endif /* AARCH64 */
+# endif
{
if (check_errno && is_negated_errno(arm_regs.ARM_r0)) {
tcp->u_rval = -1;